The field of the invention relates to signal process systems and more particularly to optical communications links used for backplane communication.
Signal processing systems are generally known. Typically, such systems (e.g., Carrier class routers, which direct internet protocol traffic; Enterprise switches, which manage corporate Ethernet-traffic; Dense Wavelength Division Multiplexing transmission equipment, which transmits telephony and data-traffic over optical fibers) are designed for some particular signal processing, switching or routing goal. Often such systems are designed by first defining a set of inputs and outputs. Inputs and outputs may be categorized according to processing requirements. Often some inputs/outputs have special processing requirements (e.g., IP encoded internet traffic, SONET telephony signals, ATM data signals, Virtual Private Networks).
To achieve overall processing goals, a number of different signal processing engines must be integrated into the overall system design. Often the individual processing engines are specified as discrete devices to take advantage of commercially available processing boards.
While such commercially available devices are effective, they often have input/output requirements which can overwhelm most electrical domain backplane communication systems. Optical domain backplane transmission systems are often the only practical alternative. However, as signal distribution becomes more complicated and large numbers of optical domain elements are placed in the optical signal path to allow processing, signal attenuation often limits topologies and possible functions. Accordingly, a need exists for a communication system backplane which is capable of operating in the optical domain and which is capable of a wide range of signal distribution scenarios.